Hitomi X-ray studies of giant radio pulses from the Crab pulsar
Hitomi X-ray studies of giant radio pulses from the Crab pulsar
复制标题
蟹状脉冲星巨型射电脉冲的瞳 X 射线研究
DOI：
10.1093/pasj/psx083
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发表时间：
2018
影响因子：
2.3
通讯作者：
et al.
中科院分区：
文献类型：
--
作者：
Hitomi Collaboration;Aya Bamba;et al.
为了寻找与蟹状星云脉冲星巨射电脉冲（GRPs）相关的巨x射线脉冲，我们在2016年3月25日，也就是在“瞳”任务失败之前，用2 - 300kev波段的x射线卫星“瞳”和1.4-1.7 GHz波段的岛岛NICT射电望远镜同时对蟹状星云脉冲星进行了观测，净曝光约为2ks。Hitomi仪器的授时性能满足授时要求，同时在主脉冲和脉间相位分别观测到约1000和100个grp，并且在主脉冲和脉间相位均未发现大射电脉冲与x射线发射的明显相关性。在2 - 300 keV波段，主脉冲和脉间GRPs变化的3 σ上限分别为0.20相宽范围内峰值通量的22%和80%。当相宽限制在0.03相时，主脉冲和脉间grp分别为25%和110%。在Hitomi卫星的上限中，4.5-10 keV和70-300 keV波段的上限是首次获得，其他波段的上限与文献报道一致。在0.20相宽范围内，主脉冲和脉间grp的数值上限分别为（2.4和9.3）× 10−11erg cm−2。脉冲剖面没有明显的变化，这表明grp起源于磁层内的局部位置。虽然光子发射粒子的数量应该暂时增加，以解释射电发射的增亮，但结果并没有在统计上排除与grp相关的变化，因为在这种条件下，可能出现的x射线增强是由于脉冲峰值通量增亮了0.02%。
To search for giant X-ray pulses correlated with the giant radio pulses (GRPs) from the Crab pulsar, we performed a simultaneous observation of the Crab pulsar with the X-ray satellite Hitomi in the 2–300 keV band and the Kashima NICT radio telescope in the 1.4–1.7 GHz band with a net exposure of about 2 ks on 2016 March 25, just before the loss of the Hitomi mission. The timing performance of the Hitomi instruments was confirmed to meet the timing requirement and about 1000 and 100 GRPs were simultaneously observed at the main pulse and inter-pulse phases, respectively, and we found no apparent correlation between the giant radio pulses and the X-ray emission in either the main pulse or inter-pulse phase. All variations are within the 2 σ fluctuations of the X-ray fluxes at the pulse peaks, and the 3 σ upper limits of variations of main pulse or inter-pulse GRPs are 22% or 80% of the peak flux in a 0.20 phase width, respectively, in the 2–300 keV band. The values for main pulse or inter-pulse GRPs become 25% or 110%, respectively, when the phase width is restricted to the 0.03 phase. Among the upper limits from the Hitomi satellite, those in the 4.5–10 keV and 70–300 keV bands are obtained for the first time, and those in other bands are consistent with previous reports. Numerically, the upper limits of the main pulse and inter-pulse GRPs in the 0.20 phase width are about (2.4 and 9.3) × 10−11erg cm−2, respectively. No significant variability in pulse profiles implies that the GRPs originated from a local place within the magnetosphere. Although the number of photon-emitting particles should temporarily increase to account for the brightening of the radio emission, the results do not statistically rule out variations correlated with the GRPs, because the possible X-ray enhancement may appear due to a >0.02% brightening of the pulse-peak flux under such conditions.